This invention pertains to heavy duty truck tractors which may incorporate sleeper boxes. More particularly, it pertains to arrangements for more efficiently providing certain electrical wiring configurations in such tractors as manufactured with and without sleeper boxes, including the wiring cables and connectors between a tractor and a trailer.
Attached hereto as Appendices A and B are respectively Standard SAE J560 and Standard ISO 3731, each of which is incorporated by reference hereinto.
Heavy duty truck tractors are manufactured with and without sleeping spaces. A tractor made without a sleeping space in comprised of a basic cab structure mounted on a basic chassis. A tractor made with a sleeping space is comprised of a basic cab structure and a sleeping compartment (commonly called a xe2x80x9csleeper boxxe2x80x9d) mounted on an extended chassis. In either case, one or more electrical outlets are provided on the exterior rear wall of the cab or the sleeper box, as appropriate. Those outlets can be made in conformance with SAE (Society of Automotive Engineers) Standard J560 as amended from time to time, last in June 1993. Those outlets receive plugs which conform to the same SAE Standard. Those plugs typically are provided at the opposite ends of a multi-wire electrical cable which is used to establish desired electrical connections between the tractor and a trailer coupled to the tractor.
Another standard pertinent to electrical interconnections between tractors and trailers of heavy duty trucks is gaining acceptance in the United States. That other standard is ISO (International Standards Organization) 3731. Connectors conforming to Standard SAE J560 are not matable to connectors conforming to Standard ISO 3731. Therefore, the outlets provided at the rear wall of the cab or sleeper box can be outlets conforming to ISO 3731. In some instances, tractors are being manufactured with parallel SAE J560 and ISO 3731 electrical cable systems, in which event both SAE J560 and ISO 3731 outlets are provided in the cab or sleeper box rear wall by the tractor manufacturer. Because each tractor manufacturer, at any given time, builds its tractors with a basic cab structure conforming to a highly standardized design, it is common for each manufacturer to use a standard, easily stocked, prefabricated wiring harness to form the electrical connections between a power distribution panel in the tractor and the outlet at the rear face of the tractor cab. Sleeper boxes, however are offered in different sizes (lengths) by the different tractor manufacturers.
It is known that tractor manufacturers do not know or address the issues presented by sleeper boxes until late in the tractor manufacturing process. The sleeper box is treated as an add-on to an extended chassis behind the cab. When a sleeper box is added behind the cab, the rear wall of the sleeper box becomes the place where the outlet for the tractor-to-trailer cable needs to be located. Heretofore, tractor manufacturers needed to stock separate cab harnesses, of different lengths related to the different lengths of sleeper boxes offered by the manufacturer, to make the connection from the tractor power distribution panel to the outlet on the sleeper box rear wall. That practice requires a part member for each different wiring harness. That complicates the tractor manufacturer""s inventory requirements and xe2x80x9csupply to the linexe2x80x9d problems for the manufacturer. Those problems include possible delays in the operation of the tractor assembly line.
Tractor manufacturers desire to stock only a minimum number of parts to provide electrical connections to a trailer regardless of whether the tractor includes a sleeper box and regardless of the length of the sleeper box.
This invention addresses and meaningfully satisfies that desire. It does so by providing a coordinated set of tractor cable modules, in the minimum number consistent with the tractor manufacturer""s need to satisfy customers"" requirements, useful to build a full range of tractors with and without sleeper boxes of different lengths. The module set is comprised of a cab cable module, a sleeper box module useful with sleeper boxes of different lengths, a disconnectible tractor-to-trailer cable module subset having two different types of cables, and a tractor-to-trailer cable module subset, of the same two different types, in which each cable is essentially permanently connected to the tractor. The two different types of tractor-to-trailer cables are straight and coiled.